The present invention relates to a security technology for a storage system comprising a storage device having one or more disks and a disk controller to control the storage device.
In a variety of fields, such as securities and medicine, laws have been introduced to regulate a preservation of data, such as electronic recordings of e-mails and their communication history, and a period of data retention. For instance, in the United States, there are the Sarbanes-Oxley Act (SOX) for corporate governance and Securities and Exchange Commission (SEC) 17a-4 adopted by the U.S. Securities and Exchange Commission. Information referred to in these laws and rules often includes customer information and corporate confidential information and thus must be protected for privacy to prevent leakage of information. These information, while they must be able to be retained for a long period of time, must also be able to be retrieved quickly when needed. Data intended to be stored for a long period has not so high a probability of being referenced and it is general practice to store them in a low-cost tape device.
However, the requirement of retrieving data quickly when needed is difficult to meet with a low-performance tape device. Under these circumstances, there is a growing demand for a storage system capable of storing such data as requires some retrieval performance on the part of the storage device, i.e., data not so high in a possibility of being referenced as those handled in a high-end storage with high performance and high reliability but not so low as those stored in a low-end storage such as a tape device. A solution has emerged which seeks to reduce management cost by optimizing a storage location according to the nature of data at different moments in time. This solution is called a data lifecycle management or an information lifecycle management.
To implement this solution, storage venders have come out with a product called a near-line storage. Many near-line storage products use Serial ATA (SATA) (also called attachment IDE) drives. The reason for the use of SATA drives for the near-line storage is that although they have somewhat less performance than fiber channel drives mostly used in high-end storage, the SATA drives have a higher performance but with somewhat higher cost than low-cost, low-end tape storage. Even in the high-end storage there is a possibility of the SATA drives being used to allow for the data lifecycle management within the high-end storage facility. In the storage system that handles data of the nature described above, it is necessary to prevent information leakage as described earlier. As one of security technologies for storage systems, a LUN masking is available (it is called differently by different vendors; here we call it a LUN masking) which logically divides a storage device into logical units (LUN) to limit an access from a host computer. As for security technology, it is common practice to use a fiber channel to establish a network connection between the host computer and the storage system. For the control of switches that are used to build the network, a technology called zoning is available. There are different types of zoning technology: a port zoning that depends on the port of a switch and WWN (World Wide Name) zoning that depends on host computer and storage system.
These technologies limit access to data stored in the storage system and thereby block unauthorized access from the host computer, thus preventing data leakage.
As for data protection technology, a WORM (Write Once, Read Many) is available which allows writing data only once and reading the written data many times but not overwriting in order to prevent falsification of data and unauthorized erasure of data. The SATA employed in many near-line storage systems has been realized by transforming the parallel transmission ATA into a serial transmission system to improve a transfer performance and expand its function (ATA-3-draft). A password system used for protecting user data in a disk is disclosed in JP-A-2004-078539.
Another security technology currently available is a password control method intended for a computer system with HDDs (hard disk drives) employing a hard disk privacy protection system in which a system BIOS (Basic Input & Output System) automatically sets a password for a particular HDD (JP-A-11-085407).
The conventional security technologies, such as LUN masking and zoning employed in a storage system having drives that are operated through a fiber channel, cannot prevent an unauthorized host computer from disguising itself as an authorized host computer and from illegally accessing the storage system, leading to possible leakage of data. To forestall this problem, it is required that the drives in the storage system themselves be able to limit access even after the storage system has been accessed. Japanese Patent Publication No. 2004-078539 (“Patent Reference 1”) describes a technology in which a system BIOS automatically processes, without making the user become aware of what is going on, the setting and unlocking of a password for hard disks of a personal computer or the like that has a password setting function in conformity with ATA. This technology disclosed in Patent Reference 1, however, is intended for personal computers and currently there is no storage system available with this password system partly because it is only a short period of time since the SATA disk-mounted products have been available in the market.
The drives often used in the storage system that are operated through the fiber channel is not in the first place given a consideration for assuring a security after their network connection is established through a password.
It is therefore an object of the present invention to provide a storage system capable of preventing information leakage by using drives that can be set with passwords as a security technology after a network connection is made.